Abstract Seismic fragilities are the probability that structural response of a system overcomes specified limit values for given seismic intensity measures. These curves are frequently defined as functions of single/multiple ordinates of the pseudo-acceleration response spectrum. Recently it was reported that this approach can lead to inaccurate estimation of the structural performance for complex non-linear multi-degree of freedom systems. This preliminary paper investigates the accuracy of fragility curves for an actual building struck by the 2016 Italian earthquake. Numerical analyses of a multi-degree of freedom structural system subjected to this earthquake are performed, considering both linear and non-linear behaviour, and used to construct scatter plots of intensity measures versus the corresponding actual maximum of the response time history. Finally, an example of the fragility curves estimated using different intensity measures is presented for both linear and nonlinear structural behaviour. It is shown that these fragilities have very large variability depending on the selected scalar or vector-valued intensity measure.

中文翻译：

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强度测量对地震脆性准确性的作用

摘要 地震脆性是系统的结构响应超过给定地震烈度测量的指定极限值的概率。这些曲线经常被定义为伪加速度响应谱的单个/多个纵坐标的函数。最近有报道称，这种方法会导致对复杂非线性多自由度系统的结构性能的估计不准确。这篇初步论文调查了 2016 年意大利地震中一座实际建筑物的脆性曲线的准确性。对受此地震作用的多自由度结构系统进行数值分析，同时考虑线性和非线性行为，并用于构建强度度量与响应时间历史的相应实际最大值的散点图。最后，针对线性和非线性结构行为，给出了使用不同强度度量估计的脆性曲线示例。结果表明，这些脆性具有非常大的可变性，具体取决于所选的标量或矢量值强度度量。